Why isn't combineReducers receiving state in Redux? - reactjs

Question

When I look at a reducer being called via combineReducers, it's not getting the state or action in the arguments.
My reducers file is this:
import { combineReducers } from 'redux';
import nav from './reducers/nav';
import pages from './reducers/pages';
import entities from './reducers/entities';
export default function(initialData) {
return function(state, action) {
if (!state) {
console.log('no state', initialData);
return initialData;
}
// This is showing state as having expected value
console.log('state', state);
return combineReducers({
nav,
pages,
entities
});
}
};
My store initialization is like this:
import reducerWrapper from './reducers';
// Initial state is defined above
var reducers = reducerWrapper(initialState),
store = Redux.createStore(reducers, initialState);
The example code on the site doesn't use a wrapper (which I had seen in some other example). I tried that too and it didn't work. I mean in either example I'm not sure how it would get state/action given what is written out. I feel like I'm missing some magic here.
Updated
Here is the reducers file now:
import { combineReducers } from 'redux';
import nav from './reducers/nav';
import pages from './reducers/pages';
import entities from './reducers/entities';
export default combineReducers({
nav,
pages,
entities
});
followed by store = Redux.createStore(reducerWrapper, initialState), also doesn't work, even when I remove the wrapping inside reducerWrapper and just export default combineReducers`

Answer 1

The answer wasn't easily seen here. The problem is that my reducer did not have a default state.
The store triggers an INIT event here: https://github.com/reactjs/redux/blob/master/src/createStore.js#L204
It then eventually gets to here:
https://github.com/reactjs/redux/blob/master/src/combineReducers.js#L52
Meaning if my reducer is function (state, action) { return state } rather than function (state='anyDefaultValue') { return state }, combineReducer will error saying that the reducer did not return state

Answer 2

combineReducers returns a function that needs to be invoked with state and action. You can just export that directly:
const rootReducer = combineReducers(...);
export default rootReducer;
Or you can wrap it as you currently are:
const rootReducer = combineReducers(...);
export default function (initialData) {
return function (state, action) {
if (!state) {
console.log('no state', initialData);
return initialData;
}
// This is showing state as having expected value
console.log('state', state);
return rootReducer(state, action);
}
}